CN208651181U - Pump for liquid salts air cooling mechanism - Google Patents

Abstract

The utility model provides a kind of pump for liquid salts air cooling mechanism, belong to fused salt conveying equipment field, including bottom plate, transmission shaft, the bearing assembly for being sheathed on the drive shaft circumference and being connect with the bottom plate, the fan on the outside of the bearing assembly, angle α between the outlet air surface of the fan and the axis of the transmission shaft is [0 °, 90 °), and the outlet air surface of the fan is corresponding with the outer middle side part of the bearing assembly.Pump for liquid salts air cooling provided by the utility model mechanism, it can be bearing assembly cooling by air-cooled mode, achieve the purpose that effective temperature-reducing, and structure is simple, not by the limitation in geographical location, it can be installed nearby with pump for liquid salts or one is installed, without carrying out excessive structure of modification on pump for liquid salts, use cost is low.

Description

Pump for liquid salts air cooling mechanism

Technical field

It is more specifically to be related to a kind of pump for liquid salts air cooling that the utility model, which belongs to fused salt conveying equipment technology field, Mechanism.

Background technique

Pump for liquid salts is the pump for being specifically used to convey high-temperature molten salt, generally uses vertical solution following formula centrifugal pump, i.e., bearing is in liquid More than face, below using no seal form, its working principle is that making the fused salt in pump generate stronger rotation fortune when impeller rotates Dynamic, the pressure of rotation center is low, and fused salt is sucked from suction inlet, simultaneously because peripheral pressure is high, so that fused salt liquid is forced out, And generate lift.In the pump for liquid salts course of work, bearing-transmission portions under heat, do not cool down will affect the normal work of pump for a long time Make, existing cooling method generally uses water-cooled cooling, extraneous cooling water pipeline, by pump for liquid salts cooling water chamber, by pump for liquid salts The effect that the heat caused by rotation axis and high-temperature molten salt conduct heat is taken away, and then pump for liquid salts is protected to run well.But this Kind of the type of cooling has the following problems: 1) vulnerable to geographical location influence, nearby without water source when, need remote water piping road, But also need to carry out antifreezing measures, it also needs to add anti-icing fluid if necessary, inconvenient for use, operating cost is high；2) source quality is wanted It asks stringent, needs to carry out water process, prevent use for a long time from causing aqueous corrosion pump for liquid salts cooling water chamber, prevent fouling, cause to dissipate Thermal effect is poor；3) cooling structure is complicated, and pump for liquid salts needs special design cooling water chamber, guarantees the integrity of its sealing, causes to melt Structure is complicated for salt pump；4) it is influenced vulnerable to external condition, when something goes wrong, cooling water is out of service for power supply at water source or water source, Cause pump for liquid salts out of service.

Utility model content

The purpose of this utility model is to provide a kind of pump for liquid salts air cooling mechanisms, existing in the prior art molten to solve Salt pump water-cooling structure is complicated, the high technical problem of use cost.

In order to achieve the above purposes, the technical solution adopted by the utility model is: provides a kind of pump for liquid salts air cooling mechanism, packet Include: bottom plate, the bearing assembly for being sheathed on the drive shaft circumference and connecting with the bottom plate, is set to the bearing group at transmission shaft Fan on the outside of part, angle α between the outlet air surface of the fan and the axis of the transmission shaft be [0 °, 90 °), and the wind The outlet air surface of fan is corresponding with the outer middle side part of the bearing assembly.

Further, the fan includes pedestal, the bracket on the pedestal and the wind set on the cantilever tip Fan head, angle α between the outlet air surface of the fan head and the axis of the transmission shaft be [0 °, 90 °), and the fan head with The middle part of the bearing assembly is corresponding.

Further, the fan head is equipped with one, between the outlet air surface of the fan head and the axis of the transmission shaft Angle α be 90 °.

Further, there are two the fan head is set, axial distribution and edge of two fan heads along the transmission shaft The radial mirror symmetry of the transmission shaft is arranged, and the outlet air surface of two fan heads is disposed opposite to each other.

Further, the angle β between the outlet air surface of two fan heads is [95 °, 115 °].

Further, the fan further includes the control panel connecting with the holder pivots, the control panel and institute State fan head electrical connection.

Further, the bottom plate is equipped with the guide rail being arranged radially along the transmission shaft, and the guide rail is close to the axis One end of bearing assembly is equipped with limited block；The base bottom is equipped with the guide groove being slidably matched with the guide rail, the pedestal On towards one end of the bearing assembly be equipped with magnetic absorption part, the limited block be equipped with for the magnetic absorption part Adsorb the ferromagnetism suction sheet of connection.

Further, the bearing assembly includes the axle sleeve for being sheathed on the drive shaft circumference, is sheathed on outside the axle sleeve The first bearing in week is sheathed on the drive shaft circumference and is used to accommodate the bearing housing of the first bearing and is set to the bearing The radiating fin group of case periphery, the bearing housing are connect with the bottom plate.

Further, there are two the radiating fin group is set, and two radiating fin groups are along the axis of the transmission shaft To distribution；The equally distributed radiating fin of the bearing housing is surrounded including multiple in each radiating fin group, and described The plate face of radiating fin is parallel with the axis of the transmission shaft.

Further, the bearing assembly includes the internal axle sleeve for being sheathed on the drive shaft circumference, is sheathed on the inner shaft It covers the second bearing of periphery, be sheathed on the internal axle sleeve periphery and the third axis between the second bearing and the bottom plate Hold, be sheathed on the outer shaft of the second bearing and the 3rd bearing periphery；Shape between the internal axle sleeve and the outer shaft It is formed at the second bearing chamber for accommodating the second bearing, between the internal axle sleeve and the outer shaft described for accommodating The 3rd bearing chamber of 3rd bearing；The outer shaft is equipped with the oil inlet passage being connected to the 3rd bearing chamber, the inner shaft It is formed between set and the outer shaft for being connected to be connected to gap of the second bearing chamber with the 3rd bearing chamber, it is described outer Axle sleeve is equipped with the oil discharge passage being connected to the second bearing chamber, and the oil inlet passage and the oil discharge passage pass through pipe respectively Road is connected to oil pump；The fan is set on the outside of the outer shaft, and the middle part of the outlet air surface of the fan and the outer shaft It is corresponding.

The beneficial effect of pump for liquid salts air cooling provided by the utility model mechanism is: compared with prior art, this is practical Novel molten salt pumps air cooling mechanism, by the way that fan is arranged on the outside of bearing assembly, and makes the blowing angle of fan always being capable of court To bearing assembly, the wind energy for blowing out it is effectively sent on the outside of bearing assembly, and then can be bearing group by air-cooled mode Part cooling, achievees the purpose that effective temperature-reducing, and structure is simple, not by the limitation in geographical location, can install nearby with pump for liquid salts Or one installation, without carrying out excessive structure of modification on pump for liquid salts, use cost is low.

Detailed description of the invention

It, below will be to embodiment or the prior art in order to illustrate more clearly of the technical scheme in the embodiment of the utility model Attached drawing needed in description is briefly described, it should be apparent that, the accompanying drawings in the following description is only that this is practical new Some embodiments of type for those of ordinary skill in the art without any creative labor, can be with It obtains other drawings based on these drawings.

Fig. 1 is the use state diagram for the pump for liquid salts air cooling mechanism that the utility model embodiment one provides；

Fig. 2 is the portion the A enlarged drawing of Fig. 1；

Fig. 3 is the left view structural representation of Fig. 2；

Fig. 4 is the use state diagram for the pump for liquid salts air cooling mechanism that the utility model embodiment two provides；

Fig. 5 is the use state diagram for the pump for liquid salts air cooling mechanism that the utility model embodiment three provides.

Wherein, each appended drawing reference in figure:

1- bottom plate；2- transmission shaft；3- bearing assembly；301- axle sleeve；302- first bearing；303- bearing housing；304- heat dissipation Fin；305- internal axle sleeve；306- second bearing；307- 3rd bearing；308- outer shaft；309- second bearing chamber；310- third Bearing bore；311- oil inlet passage；312- is connected to gap；313- oil discharge passage；4- fan；401- pedestal；402- bracket；403- wind Fan head；404- control panel；5- guide rail；6- limited block；7- guide groove；8- magnetic absorption part；9- ferromagnetism suction sheet；10- Oil pump

Specific embodiment

In order to which technical problem to be solved in the utility model, technical solution and beneficial effect is more clearly understood, with Lower combination accompanying drawings and embodiments, the present invention will be further described in detail.It should be appreciated that specific reality described herein It applies example to be only used to explain the utility model, is not used to limit the utility model.

It should be noted that it can be directly another when element is referred to as " being fixed on " or " being set to " another element On one element or indirectly on another element.When an element is known as " being connected to " another element, it can To be directly to another element or be indirectly connected on another element.

It is to be appreciated that term " length ", " width ", "upper", "lower", "front", "rear", "left", "right", "vertical", The orientation or positional relationship of the instructions such as "horizontal", "top", "bottom" "inner", "outside" is that orientation based on the figure or position are closed System, is merely for convenience of describing the present invention and simplifying the description, rather than the device or element of indication or suggestion meaning are necessary It with specific orientation, is constructed and operated in a specific orientation, therefore should not be understood as limiting the present invention.

In addition, term " first ", " second " are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance Or implicitly indicate the quantity of indicated technical characteristic.Define " first " as a result, the feature of " second " can be expressed or Implicitly include one or more of the features.The meaning of " plurality " is two or two in the description of the present invention, More than, unless otherwise specifically defined.

Also referring to Fig. 1, Fig. 4 and Fig. 5, now pump for liquid salts air cooling provided by the utility model mechanism is illustrated. Pump for liquid salts air cooling mechanism, including bottom plate 1, transmission shaft 2, the bearing group for being sheathed on 2 periphery of transmission shaft and being connect with bottom plate 1 Part 3, the fan 4 set on the outside of bearing assembly 3, the angle α between the outlet air surface of fan 4 and the axis of transmission shaft 2 be [0 °, 90 °), and the outlet air surface of fan 4 is corresponding with the outer middle side part of bearing assembly 3.

It should be noted that the lower part of transmission shaft 2 is respectively positioned on liquid level hereinafter, bottom plate 1 and bearing assembly 3 are respectively positioned in Fig. 1 It is more than liquid level；The top of bearing assembly 3 is additionally provided with the pump for liquid salts driving motor connecting with transmission shaft 2, is not shown in the figure；In Fig. 5 Non- display backpanel 1.[0 °, 90 °) it refers specifically to be more than or equal to 0 ° and less than 90 °.

When in use, pump for liquid salts ontology is assembled first, then fan 4 is mounted on bottom plate 1, and by fused salt Pump driving motor and fan 4 connect to power supply respectively, can control pump for liquid salts respectively and fan 4 works.

Pump for liquid salts air cooling provided by the utility model mechanism, compared with prior art, by being set on the outside of bearing assembly 3 Fan 4 is set, and makes the blowing angle of fan 4 always can be towards bearing assembly, the wind energy for blowing out it is effectively sent in bearing 3 outside of component, and then can be the cooling of bearing assembly 3 by air-cooled mode, achieve the purpose that effective temperature-reducing, and structure is simple, Not by the limitation in geographical location, it can be installed nearby with pump for liquid salts or one is installed, without carrying out excessive knot on pump for liquid salts Structure transformation, use cost are low；Meanwhile independent current source can be used in fan 4, the power supply of fan 4 is not influenced by external condition substantially, is made Low with failure rate, stability in use is good.

Specifically, one kind also referring to Fig. 1 to Fig. 4, as pump for liquid salts air cooling provided by the utility model mechanism Specific embodiment, fan 4 are connect with bottom plate 1, and fan 4 can be made as close as possible to bearing assembly 3, and the wind energy that fan 4 is blown out more has Effect is more fully sent at bearing assembly 3.

Further, also referring to Fig. 1 to Fig. 4, as pump for liquid salts air cooling provided by the utility model mechanism one Kind specific embodiment, fan 4 include pedestal 401, the bracket 402 on pedestal 401 and the fan set on 402 top of bracket First 403, angle α between the outlet air surface of fan head 403 and the axis of transmission shaft 2 be [0 °, 90 °), and fan head 403 and bearing The middle part of component 3 is corresponding.The wind energy that this set blows out fan head 403 is effectively blown on 3 lateral surface of bearing assembly, to guarantee Effectively radiated；Meanwhile fan head 403 contains blowing drive member, 4 overall structure of fan is simple and compact, and pedestal 401 can Be placed directly on ground or bottom plate 1 on, or by connector be connected on ground or bottom plate 1 on, facilitate making for fan 4 With.

Further, a kind of specific embodiment as pump for liquid salts air cooling provided by the utility model mechanism, bracket 402 be jack column, convenient to be adjusted to the height of fan head 403, so that fan head 403 being capable of alignment bearings component 3 Middle part.

Further, Fig. 1 and Fig. 4 is please referred to, a kind of tool as pump for liquid salts air cooling provided by the utility model mechanism Body embodiment, to improve heat dissipation effect, fan 4 is uniformly equipped at least two around transmission shaft 4.

Further, Fig. 1 and Fig. 5 is please referred to, a kind of tool as pump for liquid salts air cooling provided by the utility model mechanism Body embodiment, to simplify 4 structure of fan, fan head 403 is equipped with one, the axis of the outlet air surface and transmission shaft 2 of fan head 403 Between angle α be 90 °.The outside middle portion for the wind square impact bearing assembly 3 that fan head 403 is blown out, wind direction is in turn along transmission shaft 2 Axial dispersion open, with carry out effectively blowing heat dissipation.

Further, a kind of specific embodiment party refering to Fig. 4, as pump for liquid salts air cooling provided by the utility model mechanism Formula, there are two fan head 403 is set, two fan heads 403 along transmission shaft 2 axial distribution and along the radial mirror image pair of transmission shaft 2 Claim setting, and the outlet air surface of two fan heads 403 is disposed opposite to each other.The blowing direction of two fan heads 403 on the same fan 4 It is arranged in angle, the wind-force for dispersing blowing is stronger, and heat dissipation effect is more preferable.

Further, a kind of tool as pump for liquid salts air cooling provided by the utility model mechanism referring to FIG. 1 to FIG. 4, Body embodiment, the angle β between the outlet air surface of two fan heads 403 are [95 °, 115 °].

Further, Fig. 1, Fig. 4 and Fig. 5 are please referred to, one as pump for liquid salts air cooling provided by the utility model mechanism Kind specific embodiment, fan 4 further include the control panel 404 being rotatablely connected with bracket 402, control panel 404 and fan head 403 electrical connections.The operations such as start and stop, adjusting wind-force, the air quantity of fan head 403 may be implemented by the key on control panel 404, Use simplicity.

Specifically, Fig. 1, Fig. 4 and Fig. 5 are please referred to, one kind as pump for liquid salts air cooling provided by the utility model mechanism The top of specific embodiment, control panel 404 and bracket 401 is rotatablely connected, and rotation axis is parallel to the plate face of bottom plate 1, control The length of panel 404 processed is less than the length of bracket 401, facilitates 404 folding storage of control panel.

Specifically, a kind of specific embodiment as pump for liquid salts air cooling provided by the utility model mechanism, control plane The top of plate 404 and bracket 401 is rotatablely connected by articulation piece, and articulation piece includes the articulated shaft on bracket 402 and is set to 404 edge of control panel and the hinged set for being set in articulated shaft periphery, the outer wall of articulated shaft be equipped with for hinged set inner wall The elastic locking bed course that elasticity abuts.In the case where no external force, control panel 404 can quilt after turning to certain angle Elastic reaction force locking between elastic locking bed course and hinged set, will not be rotated further by.

Further, a kind of specific embodiment as pump for liquid salts air cooling provided by the utility model mechanism, pedestal The detachable connection methods such as threaded connector connection, grafting, clamping can be used between 401 and bottom plate 1, facilitate fan 4 and bottom plate 1 Between handling.

Further, refering to fig. 1, Fig. 2 and Fig. 4, one kind as pump for liquid salts air cooling provided by the utility model mechanism Specific embodiment, bottom plate 1 are equipped with the guide rail 5 being arranged radially along transmission shaft 2, and guide rail 5 is equipped with close to one end of bearing assembly 3 Limited block 6；401 bottom of pedestal is equipped with the guide groove 7 that is slidably matched with guide rail 5, towards the one of bearing assembly 3 on pedestal 401 End is equipped with magnetic absorption part 8, and limited block 6 is equipped with for the ferromagnetism suction sheet 9 with the absorption connection of magnetic absorption part 8.? Between pedestal 401 and bottom plate 1 after grafting in place, can directly firm banking 401, positioning conveniently, it be loaded and unloaded simple by magnetic absorption.

Specifically, a kind of specific embodiment as pump for liquid salts air cooling provided by the utility model mechanism, magnetism are inhaled Attachment is magnet.

Specifically, a kind of specific embodiment as pump for liquid salts air cooling provided by the utility model mechanism, magnetism are inhaled Attachment is electromagnet, and electromagnet is electrically connected with control panel 404.

Further, Fig. 1 and Fig. 4 is please referred to, a kind of tool as pump for liquid salts air cooling provided by the utility model mechanism Body embodiment, bearing assembly 3 include the axle sleeve 301 for being sheathed on 2 periphery of transmission shaft, the first axle for being sheathed on 301 periphery of axle sleeve 302 are held, 2 periphery of transmission shaft is sheathed on and for accommodating the bearing housing 303 of first bearing 302 and set on 303 periphery of bearing housing Radiating fin group, bearing housing 303 are connect with bottom plate 1.Bearing housing 303 can accommodate at least one first bearing 302, while bearing housing Lubricating oil can be held in 303, lubricating action is played to bearing, can also play certain heat-absorbing action, make first bearing 302 and its The heat of link position can be faster by forming air flow channel, adding on conducting lubricant oil to bearing housing 303 in radiating fin group The heat exchanger effectiveness of fast bearing housing 303 and air.

Further, Fig. 1 and Fig. 4 is please referred to, a kind of tool as pump for liquid salts air cooling provided by the utility model mechanism Body embodiment, for the radiating efficiency for further increasing radiating fin group, there are two radiating fin group is set, and two radiating fins Axial direction distribution of the group along transmission shaft 2；It include multiple around the equally distributed radiating fin of bearing housing 303 in each radiating fin group Piece 304, and the plate face of radiating fin 304 is parallel with the axis of transmission shaft 2.Air is formed between adjacent radiating fin 304 Runner, each air flow channel keep the contact area of air flow channel and bearing housing 303 biggish each parallel to the axis of transmission shaft 2 Speed air flow is also improved to the greatest extent simultaneously, and heat dissipation effect is best.

Further, referring to Fig. 5, a kind of specific implementation as pump for liquid salts air cooling provided by the utility model mechanism Mode, bearing assembly 3 include the internal axle sleeve 305 for being sheathed on 2 periphery of transmission shaft, the second bearing for being sheathed on 305 periphery of internal axle sleeve 306,305 periphery of internal axle sleeve and 3rd bearing 307 between second bearing 306 and bottom plate 1 are sheathed on, is sheathed on the second axis Hold the outer shaft 308 of 306 and 307 periphery of 3rd bearing；It is formed between internal axle sleeve 305 and outer shaft 308 for accommodating the second axis The second bearing chamber 309 for holding 306 forms the third axis for accommodating 3rd bearing 307 between internal axle sleeve 305 and outer shaft 308 Hold chamber 310；Outer shaft 305 is equipped with the oil inlet passage 311 being connected to 3rd bearing chamber 310, internal axle sleeve 305 and outer shaft 308 Between formed and be connected to gap 312 for be connected to second bearing chamber 309 and 3rd bearing chamber 310, outer shaft 308 is equipped with and the The oil discharge passage 313 of two bearing bores 309 connection, oil inlet passage 311 and oil discharge passage 313 are connected by pipeline and oil pump 10 respectively It is logical；Fan 4 is set to 308 outside of outer shaft, and the outlet air surface of fan 4 is corresponding with the middle part of outer shaft 308.Wherein, it is connected to gap 312 be ring-type.

Lubricating oil enters in oil inlet passage 311 through oil pump 10, subsequently flows into and is full of second bearing chamber 309, then pass through Connection gap 312 enters and is full of 3rd bearing chamber 310, is finally discharged under the swabbing action of oil pump 10 through oil discharge passage 313 The flowing of bearing assembly 3, lubricating oil forms a circulation loop, and lubricating oil not only acts as profit when 3 inside of bearing assembly Sliding effect, moreover it is possible to the partial heat of bearing assembly 3 be taken away, can be further improved heat dissipation effect with the cooperation of fan 4.Lubricating oil exists A degree of cooling can be obtained in pipeline, and partial heat can also be absorbed after turning again in bearing assembly 3.

Specifically, settable heat exchanger assembly on pipeline improves radiating efficiency to cool down to lubricating oil.

The above is only the preferred embodiment of the utility model only, is not intended to limit the utility model, all at this Made any modifications, equivalent replacements, and improvements etc., should be included in the utility model within the spirit and principle of utility model Protection scope within.

Claims (10)

1. pump for liquid salts air cooling mechanism, it is characterised in that: including bottom plate, transmission shaft, be sheathed on the drive shaft circumference and with institute Bearing assembly, the fan on the outside of the bearing assembly for stating bottom plate connection, the outlet air surface of the fan and the transmission shaft Axis between angle α be [0 °, 90 °), and the outlet air surface of the fan is corresponding with the outer middle side part of the bearing assembly.

2. pump for liquid salts air cooling as described in claim 1 mechanism, it is characterised in that: the fan includes pedestal, set on described Bracket on pedestal and the fan head set on the cantilever tip, the axis of the outlet air surface of the fan head and the transmission shaft it Between angle α be [0 °, 90 °), and the fan head is corresponding with the middle part of the bearing assembly.

3. pump for liquid salts air cooling as claimed in claim 2 mechanism, it is characterised in that: the fan head is equipped with one, the wind Fanning the angle α between the outlet air surface of head and the axis of the transmission shaft is 90 °.

4. pump for liquid salts air cooling as claimed in claim 2 mechanism, it is characterised in that: there are two the fan head is set, two institutes Fan head is stated along the axial distribution of the transmission shaft and is arranged along the radial mirror symmetry of the transmission shaft, and two fans The outlet air surface of head is disposed opposite to each other.

5. pump for liquid salts air cooling as claimed in claim 4 mechanism, it is characterised in that: between the outlet air surface of two fan heads Angle β be [95 °, 115 °].

6. pump for liquid salts air cooling as claimed in claim 2 mechanism, it is characterised in that: the fan further includes turning with the bracket The control panel of dynamic connection, the control panel are electrically connected with the fan head.

7. pump for liquid salts air cooling as claimed in claim 2 mechanism, it is characterised in that: the bottom plate is equipped with along the transmission shaft The guide rail being arranged radially, the guide rail are equipped with limited block close to one end of the bearing assembly；The base bottom be equipped with The guide groove that the guide rail is slidably matched is equipped with magnetic absorption part towards one end of the bearing assembly on the pedestal, described Limited block is equipped with for the ferromagnetism suction sheet with magnetic absorption part absorption connection.

8. the pump for liquid salts air cooling mechanism as described in any one of claim 1-7, it is characterised in that: the bearing assembly packet It includes and is sheathed on the axle sleeve of the drive shaft circumference, the first bearing that is sheathed on the axle sleeve periphery, be sheathed on outside the transmission shaft Week and the bearing housing for accommodating the first bearing and radiating fin group set on the bearing housing periphery, the bearing housing with The bottom plate connection.

9. pump for liquid salts air cooling as claimed in claim 8 mechanism, it is characterised in that: there are two the radiating fin group is set, and Axial direction distribution of two radiating fin groups along the transmission shaft；It include multiple around institute in each radiating fin group The equally distributed radiating fin of bearing housing is stated, and the plate face of the radiating fin is parallel with the axis of the transmission shaft.

10. the pump for liquid salts air cooling mechanism as described in any one of claim 1-7, it is characterised in that: the bearing assembly Including being sheathed on the internal axle sleeve of the drive shaft circumference, the second bearing for being sheathed on the internal axle sleeve periphery, being sheathed in described Axle sleeve periphery and 3rd bearing between the second bearing and the bottom plate are sheathed on the second bearing and described The outer shaft of three bearing peripheries；The second axis for accommodating the second bearing is formed between the internal axle sleeve and the outer shaft Chamber is held, forms the 3rd bearing chamber for accommodating the 3rd bearing between the internal axle sleeve and the outer shaft；The outer shaft The oil inlet passage for being equipped with and being connected to the 3rd bearing chamber is put on, is formed between the internal axle sleeve and the outer shaft for being connected to The gap that is connected to of the second bearing chamber and the 3rd bearing chamber, the outer shaft are equipped with and are connected to the second bearing chamber Oil discharge passage, the oil inlet passage and the oil discharge passage pass through pipeline respectively and are connected to oil pump；The fan is set to described On the outside of outer shaft, and the outlet air surface of the fan is corresponding with the middle part of the outer shaft.